Paints, enamels, japans, and the like



Patented Mar. 13, 1928.

UNITED STATES PATENT OFFICE.

DANIEL GARDNER, OF WEYBRIDGE, ENGLAND.

PA INTS, ENAKELSQ J'AQA NS, AND THE LIKE.

Ho Drawing. Application filed August 1922, Serial No. 856,119, and in Great Britain August 21, 1888.

This invention relates to improvements in paints, enamels, japans and the like, and has. for its object the provision of a non-aqueous colloidal lead-free paint, and a method'of 8 manufacturing such paint, more particularly white and light shades of aint, from oxides of titanium, zirconium, mo yhdenum, cerium, thorium, tungsten, vanadium, niobium, tantalum or uranium, and other metals exoe t 10 lead of the fourth and higher grou s of t e periodic system. When using suc oxides for making up a pigment, special care has to be taken with regard to the ingredients from which the proposed pi cut is to be formed.

In my prior Britls Patent No. 195,996, I describe a process for manufacturing paints containing as pigments compounds of metals of the fourth, fifth and sixth groups of the periodic system, in which the filler" and base components used are both compounds of metals of the same group. is to be noted that I do not herein claim any matter whichis claimed or described in my prior British Patent 195,996). In contradistinction to this, the present invention primarily consists in a non-aqueous colloidal cad-free paint, enamel, 'apan or the like, and the method of manu acturing the same, in which all constituents of the pigment introduced into the vehicle are compounds of the same metal, "the oxide of the baseconstituent of which pigment is positively charged relatively to the charge carried by the oxide or oxides forming the filler.

The invention also consists in a paint, enamel, japan or the like of the kindindicated in the preceding paragraph, and the method of manufacturing the same, in which all the tiller ingredients of the pigment are calcined in the presence of the base used, and the vehicles are preferably pretreated in the presence of the same base.

The invention also consists in apaint, enamel, japan or the like of the kind indicated above, and the method of manufacturing the same, in which the ingredients are mixed in molecular proportions so that upon application of the paint, no galvanic action can take place.

The invention further consists in the nonaqueous colloidal lead-free paints, enamels, japans and the like, when manufactured by the processes herein described and claimed.

It is to be understood that throughout the specification the terms, base, filler, and pigment are to be interpreted as follows:

Base.

Base is the substance which gives the pigment its covering power, its color, its opacity, and its tinctorial power.

Filler.

Pigment consists of a mixture of base and filler, and in this invention the substances formlng the pigments are calcined together.

Electric charge.

In order to explain this invention, it is assumed that the pigment in the coating composition is in a colloidal solution. Substances in such solutions are known to be electrically charged, and their relative charge is either positive or negative, according to the substance with which they are compared. Throughout the specification the electric char s referred to are always to be understoo as relative charges. The charge carried by the oxide forming the base is posi tive relativel to the char e carried by the com ounds' orming the ller. As an examp e, it may be stated that titanium oxide when in this condition is positively charged when compared with silica, but negatively chargediwhen compared with titanium tr1 oxide (Ti O and calcium oxide is positivelylcharged when compared with titanium oxide. It is to be borne in mind that individually the oxides carry their electric charge potentially, and the actual char e appears only after the introduction of t e pigment into the vehicle, in which the pig ment constituents are present in colloidal state. The potentially positively and negatively charged oxides form together in the colloidal state the stable compound.

Bearing these points mind, and in order lOl ' that the carrying of the invention into efiect may be understood, I will now describe in detail the modifi ations thereof, and then the e taken when PI'OdUGing and where the oxide or oxides acting as a lar lines other oxides may be a after.

filler have a negative charge relatively to the charge carried by the oxide forming the base, and are an element or elements of the.

same group of the periodic system as the metal occurring in the base. These oxides, when undergoing the process of calcination, form a stable dompound with the oxide of the base. It will be understood therefore that the oxides become (and are, when introduced -into the vehicle).'a compound of'the metal occurring in the base. The oxide of the base chosen must possess good covering capacity, and satisf all the requirements of a good pigment. l hroughout the aint all other ingredients, for example, the rier, are compounds of the metal occurring in the base.

.In considering this case, thoria may be taken,

for example, as the base of th pigment, and mixed with the filler and ot er ingredients in the Fanner more fully-described hereure silica .or kie'sel hr in powdered form are used as the salt of the metal of the base "is .utiliaed as a hereinafter described.-. Obviousl on "simiinstead of thorium oxide. .The thorium oxide may-be produced in any desired manner, but that-- prepared in the following'manner has beenound particularly effective. Obtain freshly precipitated thorium hydroxide alfil carefully dr it'first at 100 0., and, then at a slightly higher temperature, say 120 0-, and

finally pass through a' sieve of say, 300 mesh or finer. The thorium oxide so obtained is then calcined with the-filler. The proportions of the constituents of a specificexample of paint prepared in accordance with the foregoingexampleisas fol- -lo ws:-'- f I i y I Percent-Parent Pi ent, thorium oxide '35. silica- .14.20 Vehicle, linseed oil 40,00} 2 turpentine '9, 20 Drier, thorium resin'ate 0.8

this example, the thorium oxide carries or to form a good plgment, to which, say, thorium 'si1i-- cate or thoriu'mtitanate or thorium'zirconate' may be added.- An organic or inorganic drier.- The oils and other vehiclesare'dpre vR'efm'mng treated in the presence of the base-use mvemlon the the positive charge, while the silica carriesthe negative charge when in colloidal state. In'anoth'er embodiment of the invention,

the oxide of the filler has covering power, and is negatively charged, and may in addition be mixed with other negatively charged oxides of metals occurring in the same group of the periodic system as the metal contained in the other constituent of the filler. These oxides, when undergoing the process of. calfcination, form a stablecompound with the I It will be understoood' therefore that the oxides become (and are,

oxide of the base.

when introduced into the vehicle) a. comound of the metal occurringin the base. 5 an example, tltamum oxide may be named as asuitable filler,sat1sfy1ng-the conditions for covering power and-having a.negative ,Magnesm is suggested as a suitable charge. base. I

In a paint prepared. in accordance with this embodiment of the invention, the pro portions of the constituents in a specific example are as follows I Per cent Per cent In this, example, the magnesia carries a p031 'tive ha fge, and the tit m Oxide and silica carry negative charges'when in colloidal state. 1

now to another embodiment of different degree of oxidation, one being relafiller comprises the oxide having a negative igment contains two. OXIdQS of the same e ement, each having a charge, and may in addition contain other negatively charged oxides of metals in the same group of the periodic system as the metal of the base. These oxides, when undergoing the process of calcinatiom form H a stable compound with the oxide of the.

base. 'It will be understood therefore that the oxides become (and are, when introduced into the vehicle) a 'com' oundof the metal o-conform wifhithe stipulations already made, all other ingredioccurring in the base.

ents for. example, the drier) introduced into t e "vehicle are produced from compounds, of the same metal as forms the base.

As an example of an oxide to satisfy the without thejaddition of silica.

requirementsjof "this case, titanium trioxidef maybe-mentioned. a suitable base,'wl 1ile titan1um'ox1de is used as a filler, with or .In the specific example of paint prepared I i in accordance with this embodiment of themama invention, the proportions of the constituents are as follows Per cent Per cent Titanium trioxide 32.75} 0' Titanium oxide -Q 17. Vehicle, linseed oil 40. 0O} 4 turpentine"; 9. 20 Drier, titanium borate 0. 8

In this example, the titanium trioxide carries a positive charge while the titanium oxide carries a negative charge when in colloidal state. I

When .carrying the invention into efi'ect in such manner as to incorporate one or other of the foregoing examples, the ingredients of the paint are mixed in molecular proportions in order that upon application of the paint no galvanic action can take place. Special care is taken to calcine the base and filler together, after they have been carefully ground or powdered to pass through a sieve of the desired mesh, say 300'. mesh or finer. The pigment so formed is calcined in order to remove the last traces of moisture. After calcination, the resulting product if necessary is again passed through a sieve of fine mesh. The calcination temperature varies for different bases, and the minimum temperatures may be as far apart as 450 C. and 1200 0.,

depending upon the oxide with covering power used. In the example quoted in the description of the, first embodiment of the invention, calcination' is carried out at 600 C.

Special care is taken in the production of white pigments as their color can be seriouslyalfected by intermediate reactions or the actions of nitrogen from the air. As some driers do not dry completely throughout the painting layer, and thus tend to produce peeling and other like defects, it is desirable to introduce into the igments an additional ingredient capable 0F modifying the action of drying. Forexample, a phosphate or a borate of the metal chosen as base may be used, and if not volatile at the calcination temperature, can be introduced into the mixture before calcination. Should, however, an organic salt of the metal chosen as base be used as drier, it can only be introduced at a subse uent stage in the making up of the paint. rom these remarks it is to be understood that if, for example, a resinate is used as the drier, there is a possibility that drying may be effected too quickly, and should preferably be retarded by the introduction of, for example, a borate of the metal chosen as base. On the other hand, if a borate be used as a drier, and the action of drying be too slow, a phosphate of the metal chosen as base may be added to hasten the drying.

It is of great importance when utilizing oxides of zirconium, titanium, molybdenum, having a positive charge actmg as base and a 9 cerium, thorium, tungsten, v vanadium, :nio-

bium, tantalum or uranium and other metals of the fourth and higher groups of the periodic system that the oil used s ould receive careful pro-treatment. For exam le, 'it is desirable if the oil is to be thickene orpolymerized or even boiled in the usual way for the pperation to take place Without the addition of any oxides or salts not used in the pigment, and preferably in the presence of the base used. Any other ingredients for example, turpentine or othersubstances used for a like purpose introduced into the vehicle are pretreated on the lines indicated as .de sirable in the case of the oil. It is desirable that these ingredients be moisture-free. The

pigment according to the oil or other vehicles employed will be about 10 per cent to 60 per cent ofxthe total amount of materials use In the production of a colored paint, similar precautions must receive consideration, but the calcining temperature is of minor importance. In the production of a white paint, however, on the above lines, the temperature should be ke t as low as possible for the calcining of t e pigment. Similar conditions will be met with if other oxides ofhigh covering power are used. Titanium titanate is a stable compound possessing in the highest degree the high covering power of titanium oxide,and is particularly useful for the production of the darker shades of paint. The presence of silica or silicates distinctly improves the color, more particularly if lighter shades of paint are required.

What I claim and desire to secure by Letters Patent is: v

1. A non-aqueous colloidal lead-free paint,

2. A non-aqueous colloidal lead-free paint,

enamel, japan or the like, as claimed in claim 1, having a vehicle containing a pigment in colloidal state, which pigment comprises an oxidehaving a ositive charge acting as base and an oxi e or oxides ne atively charged relative to the base oxide acting as filler, the oxides to ether forming a compound of the metal 0 the base, and having at least one drier in the paint or the like, said drier being also a compound of the metal in the base.

3. A non-aqueous colloidal lead-free paint, enamel, japan or the like, as claimed in-claim 1, having a vehicle containing a pigment in colloidal state, which co prises, an oxide negatively charged oxide or oxides acting v 1, in which all the ingredients of the pigment have been calcined in the presence of the base used.

5. A non-aqueous colloidal lead-free paint, enamel, japan or the like, as claimed inclaim 1, in which the vehicles have been pre-treated in the presence of the same base.

6. A non-aqueous colloidal lead-free paint,

enamel, apan or the like as claimed in claim 1, inclu ing a drier which is moisture-free and is a compound of the metal used in the base of the pigment. I

7. A non-aqueous colloidal lead-free paint, enamel, japan or the like as claimed in claim 1 including an additional ingredient capable of modifying the action of drying, said ingredient being moisture-free and being a compound of the metal used in the base of the pigment, said ingredient functioning to thoroughly dry the paint; enamel, japan or the like, when the same is used as a coating.

In testimony whereof I have signed my name to this specification.

DANIEL GARDNER. 

